Field of Invention
The present invention relates to a paper correction apparatus, an image forming system, a non-transitory computer readable medium on which a paper correction program is recorded.
Description of Related Art
Heretofore, a paper correction apparatus is known which intervenes between an image forming apparatus and a finisher in order to correct a curl of a sheet for preventing troubles due to the curl of the sheet from occurring in the finisher located in the subsequent stage. This type of the paper correction apparatus corrects a curl of a sheet by making use of a paper conveying route which is curved in the reverse direction to the curl direction (the protruding direction of the curling sheet) to correct the curl of the sheet. Specifically speaking, a paper correction mechanism is constructed by a conveyor belt, which comes in contact with one side of a sheet, and a cylindrical shaft member which extends in the width direction of the conveyor belt in the other side of the sheet to form a curved paper conveying route for correcting the sheet by pushing the cylindrical shaft member into the conveyor belt (for example, refer to Japanese Patent Published Application No. 2003-137467).
However, when this paper correction apparatus corrects a warped sheet, the stronger the paper correction is, the greater the degree of the curve of the conveyor belt has to be so that the paper conveying length becomes longer. The timing of supplying a sheet to the subsequent finisher can therefore differ depending upon a curl correcting force. For example, in the case where the first sheet is strongly corrected and the second sheet is weekly corrected, the first sheet arrives at the finisher with a great delay but the second sheet arrives at the finisher with a little delay.
Such different timings (sheet intervals) of supplying sheets to the finisher result in the reduction of the productivity of post-printing processes in the finisher. For example, if the sheet interval is too small, paper jam tends to occur in the finisher. Conversely, if the sheet interval is too large, the waiting time of the next sheet becomes longer.